The present invention generally relates to the field of control apparatus. Specifically, the present invention relates to the field of controllers and apparatus for the control of temperature in a plurality of zones.
Traditionally, heating and cooling of structures, such as residential and commercial buildings was accomplished by a system of vents or pipes, connected to a central unit, which routed a fluid, such as air or a liquid, to the different spaces within the structure, wherein the analysis of whether heat or cooling was necessary, was determined by a single sensor.
Today, some systems have at least one sensor in each space, or in a plurality of spaces, to facilitate different temperature conditioning of the different spaces, thereby allowing the spaces to have different temperatures. Some of these apparatus may simply moderate the flow of fluid to the spaces by turning a fan or pump on and off, or by changing the speed of the fan or pump. Alternatively, many apparatus typically have one or more valves or dampers connected to each conduit, through which the fluid is communicated to the spaces, that are adjustable to help disperse the correct amount of conditioned fluid into the space.
Although some apparatus have several controllers that determine when and where to disperse the conditioned fluid, many apparatus are devised with a central controller that controls the conditioning of all of the spaces through the processing of data obtained by the plurality of sensors within each of the spaces.
Initially, these apparatus had problems with the control of the conditioning unit that supplies the conditioned fluid to the spaces because the demand for conditioning resulted in short breaks between its run times, thereby reducing the effectiveness and longevity of the unit.
Recently, apparatus have been developed that incorporated a method for determining the conditioning demand in the space having the greatest demand for conditioning and utilized the requirements of this space to dictate when the conditioning device was actuated. In a further improvement upon this principle, other apparatus have been developed that, while utilizing the zone of greatest demand to dictate when the conditioning device was actuated, the apparatus synchronized the distribution of fluid to all zones to coincide with the actuation of the conditioning device, thereby conditioning all zones needing conditioning during the same period. This system is more efficient and reduces the wear and tear of the conditioning device and, thereby, increases the longevity of the system by reducing the amount of time the device is running and by reducing the amount of short breaks between run times.
Although this approach has been successful, the present invention discloses another more sophisticated and improved solution to this problem.
The present invention further refines the idea of utilizing zone control to reduce the run time of the conditioning device and to further reduce the amount of short breaks between running periods. The present invention includes a controller, multiple zone control apparatus, and method for controlling temperature independently in each zone, for use in a structure having an interior divided into a plurality of zones.
The controller is constructed and arranged to control the temperature in each zone by actuating a temperature-affecting device to communicate a temperature conditioned fluid to the zone. The controller is constructed and arranged to determine a zone temperature error for each of the zones based upon the difference between a predetermined temperature and the temperature represented by a signal sent from a sensor located in the zone in which the error is to be determined. The controller also is constructed and arranged to compare the errors of a plurality of zones to determine the zone with the greatest of the errors among these zones. The controller has a predetermined on/off cycle for each zone for actuating the temperature-affecting device such that when the cycle is in an xe2x80x9conxe2x80x9d condition, the temperature-affecting device communicates fluid to the zone and when the cycle is in an xe2x80x9coffxe2x80x9d condition, the device does not communicate fluid to the zone. The controller is constructed and arranged to actuate the temperature-affecting device when the on/off cycle of the zone of greatest error or demand dictates such actuation.
The controller also has a synchronizing mechanism to synchronize the on/off cycles of a plurality of zones when a predetermined triggering event occurs. For example, the triggering event may be the changing of the zone of greatest error or demand from an xe2x80x9conxe2x80x9d condition to an xe2x80x9coffxe2x80x9d condition, from an xe2x80x9coffxe2x80x9d condition to an xe2x80x9conxe2x80x9d condition, or the changing of the zone of greatest error or demand from a first zone to a second zone. The synchronizing mechanism may set the on/off cycles of a plurality of zones to the beginning of either the xe2x80x9conxe2x80x9d cycle or the xe2x80x9coffxe2x80x9d cycle.
Other objects and advantages of the present invention will be apparent from the following description of a preferred embodiment thereof and from the attached drawing.